In order to create contents easily understandable for persons who have a visual disability or a learning disability, Braille work or transliteration work is performed on documents. Most of such works are performed in small-sized projects voluntarily. Improvement in recent years of a computer environment, particularly, with the development of voice synthesis technology, makes it possible to replace or support reading voices conventionally read aloud by real voices with voice synthesis. Particularly, technological innovation in terminals, which had drawbacks in voice quality and function, has made it possible to read aloud text data including Kanji (Chinese syllabary characters) and Kana (Japanese syllabary characters) by synthesized voices having a natural voice feel using a voice synthesis function in recent years. The voice synthesis function is utilized in a standalone environment where an application achieving the voice synthesis function is installed in each terminal and a client server environment where the application is installed in a server, for example.